Improvement in machines for sharpening twist-drills



2 sheets s heet l.

Patented July 2 1 N0.l53,40l.

THE GRAFHIC CO.PHDTD-UTH,39&4 l PARK PLACE, N.Y.

2 Sheets--Sheet 2.

I c. VAN HAAGEN. Machines for Sharpening Twist Drills.

Patented July 21,1874.-

N0.l53,40l.

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UNITED STATES PATENT DE IGE.

cLAUs vA HAAGEN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR To HIMSELF AND ANTHONY vAN HAAGEN, or sAME PLACE.

IMPROVEMENT IN MACHINES FOR SHARPENENG TWIST-DRILLS.

Specification forming part of Letters Patent No. l53, l0l,'dated July 21, 1874; application filed June 1, 1874.

. of which the following is a specification:

The object of my invention is to impart an accurate cutting-edge to a twist bit or drill by mechanism which Iwill now proceed to describe.

In order that my invention may be fully understood, it will be well to explain in the outset that a twist-drill must have a chisel-point, w, of the character illustrated in Figures 1 and2 of the accompanying drawing; that the cutting-edges 3 3 must be perfectly straight, and inclined at precisely similar angles, and that the portions 11 o of the end of the drill must be so reduced, from the cutting-edges to the points w w, as to insure the existence, under all circumstances, of the above mentioned chiselended termination .70 of the drill.

Referring to the explanatory diagram, Figs, 1 and 3, in which A represents a grindstone, and B the twist-drill, if the drill be simply turned in the direction of the arrow 1, while its cutting end is applied to the stone, the result will be inefiicient cutting-edges y y, the absence of the chisel-point ac and portions 1; e, at the same angle throughout in respect to the longitudinal central line of the drill whereas each of the said portions o should present an angle gradually diminishing,orbecoming more acute,

from the cutting-edge y to the point w, in re-' spect to the said central line. This conformation of the end of the drill can be obtained by simply moving the said drill, Fig. 3, in the direction of the arrow 2, as shown by dotted lines, while the end of the drill is applied to the stone, and while it is turned on its own axis, a slight forward movement being at the the bit B, the center lines of both of which should be on the same horizontal plane. The grindstone -shaft to turns in suitable bearings b b on the carriage or-head stock E, and the latter slides on inclined guides on the bedplate, on which it can be moved to and fro by a lever, G, and connectin g-rod G, or equivalent appliances. The carriage F is pivoted to the bedplate bya bolt, H, the central line of which should be on a vertical line parallel with the shaft a, and tangential to the periphery of the stone; and, in order that these relative positions may be preserved, thesaid boltis rendered adjustable in a slot, (1, in the bed-pl ate at right angles to the shaft to, and the carriage Fhas a slot, 0, at right angles to the slot (1, which permits it to be adjusted on the bolt. (Sec detached plan View, Fig. 6.) The bit B is fit: ted into a tapering socket in a hollow shaft, I, which is supported by an adjustable headstock, J, and fixed standard K, onthe carriage F, the said shaft admitting of beingturned independently of a sleeve, L, in the.

head-stock J, to the extent permitted by a spiral slot, 0, into which a pin, e, on the shaft projects; or the slot may be in the shaft, and the pin on the sleeve. The shaft admits, also, of being moved longitudinally through, without turning independently of, a sleeve, M, in the standard K. (See Fig. 5, sectional plan view, Fig. 7, and transverse section, Fig. 8, on the line 3, 4, Fig. 5.) A ring, P, adapted to a recess in the head-stock J, encircles the sleeve L, and is provided with a set screw, h, by which it can be firmly secured to the said sleeve, thus preventing all longitudinal movement of the latter, but permitting it to be turned with the said ring to the extent of exactly one-half a revolution in either direction, which is determined by a springstud, 'i, of the head-stock, adapted to either of two recesses, t, at opposite points on the ring.

Simple stops on the head-stock, and a pro-' jection or projections on the ring, might be substituted for the above-mentioned springstud and recesses as a means of determining the extent of the movement of the said ring.

The sleeve M has a free rotary movement in a the sleeve.

the standard K, but is prevented from moving longitudinally therein; and to the said sleeve is hung loosely a wheel, Q, provided with a set-screw, k, by which it can be made fast to This wheel is connected, by a universally-jointed rod, m, to a projection, 12, of the bed-plate, so that when the said wheel is turned from the position shown in the end View, Fig. 9, to that indicated in the end view, Fig. 10, the result must be a movement of the carriage F upon its pivot-bolt H inthe direction of the arrow 2, Fig. 4:; and if the said wheel be made fast to the sleeve M, by means of its set-screw k, the result must be a partial rotation of the shaft I and bit Bin the direction of the arrow 1, Fig. 4; while, if the sleeve L be made fast to the ring P by means of the set-screw h, when the said ring is retained in the position shown in Fig. 7, the pin 0 on the shaft will traverse the spiral sloteof the sleeve L, and the result must be a forward movement of the said shaft and bit,- as indicated by the arrow 3, Fig. 4. In this way the compound movement before described is imparted to the bit, while it is subjected to the action of the stone A; and when one side has been sharpened, it is only necessary to loosen the setscrew k of the wheel Q in order to permit the shaft and the bit to be turned half-way round, by an adjustment of the ring P and sleeve L, to the position indicated by dotted lines in Fig. 8, and to then tighten the set-screw k, and

again turn the wheel Q, which will cause a precisely similar compound movement to be imparted to the drill while its opposite side is subjected to the stone.

The drill, when sharpened, may be forced out of the socket in the shaft I by a rod, T, adapted to the hollow portion of the said shaft at the rear of the socket. (See Fig. 5.)

The yielding or sagging of the drill while subjected to the action of the stoneis prevented by supporting the outer rod of the said drill in an adjustable triangular rest, S, secured to the carriage F. l

The object in rendering the headstocks J adjustable upon the carriage is to adapt the machine to different lengths of drills; and the shaft I and sleeve L are also rendered longitudinally adjustable'for the same purpose.

I propose, in some instances, to modify the machine by pivoting the carriage E and grindstone instead of the tool-holding carriage F, in which case the latter would be fixed.

I claim as my invention- 1. The combination of the tool-holding shaft I with the sleeve L, when one of the said parts has a spiral slot, e, and the other a pin, 0, adapted to the said slot, all substantially as and for the purposes specified.

2. The combination, substantially as described, of the head stock J, the adjustable ringP and its set-screw, the sleeve L, and the tool-holding shaft I.

3. The combination of the adjustable ring P with a stop or stops,t', 011 the head-stock J, for

determining the extent of the rotary movement of the said ring, all substantially as and for the purpose specified.

4. The combination of the pivoted carriage F, wheel Q, connecting-rod m, bed -plate D, and connecting devices, substantially as described, whereby the said carriage may be turned upon its pivot by the rotation of the wheel, all substantially as specified.

5. The combination of the shaft I, sleeve M, and wheel Q, with its set-screw 7a.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

0. VAN HAAGEN.

Witnesses:

WM. A. STEEL, HARRY SMITH. 

